· Donora, Pennsylvania is a mill town 24 miles southeast of Pittsburgh on the Monongahela River. · The Donora Smog was an air inversion which trapped industrial pollutants in the air for 6 days· An inversion occurs when the ground air is cooler than the air above it (reversed conditions in the atmosphere) and when this happens man made pollutants are trapped in the air, causing smog. · It killed 20 people and permanently damaged the lungs of 7,000 and the event raised public awareness that air pollution can be lethal and cause serious damage to one’s health.· The source of the pollution was from the U.S. Steel smelting plants and Donora Zinc Works plantBibliography http://www.pollutionissues.com/Co-Ea/Donora-Pennsylvania.htmlhttp://www.wired.com/science/discoveries/news/2007/10/dayintech_1026#